So why do we continue to act this way today? Is it cultural? If so then why haven't we overcome it. I can say it cannot be baked into our genes, because of th

So why do we continue to act this way today? Is it cultural? If so then why haven't we overcome it. I can say it cannot be baked into our genes, because of the timespan it takes for such a thing to occur. The last time humanity had any real genetic shifts, were when the population was small enough that (to a modern day observer) everyone would look like they were of the same race.